Several theoretical frameworks were proposed to explain the
color confinement mechanism (in Landau gauge), such as the Gribov-Zwanziger
scenario [1]}, [2]} and the scaling solution of
Dyson-Schwinger equations [3]}, to name only two of them.
Both descriptions — in their original
formulations — predicted that the gluon propagator vanishes at zero momentum and
the ghost propagator has an enhanced singularity, i.e. it is more singular than
\(1/p^2\)  in the IR limit. These properties were verified with lattice
numerical simulations, using large lattice volumes, in 2 space-time
dimensions [4]}, [5]}.
On the contrary, in 3 and in 4 dimensions [6]}, [4]}, [8]}, [5]}, lattice data showed that the ghost propagator, \(G(p^2)\) , is not
enhanced, i.e. \(G(p^2 \approx 0) \sim 1/p^2\) , and that the gluon
propagator does not go to zero at the origin.
These results for the propagators in the IR regime motivated novel
theoretical models that are in accordance with lattice simulations, such
as the decoupling solution of Dyson-Schwinger
equations [10]}, [11]}, the Refined Gribov-Zwanziger
scenario [12]}, [13]}, [14]} and the Curci-Ferrari
model [15]}, [16]}.
